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| Registros recuperados: 59 | |
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| Lens, F.; Schönenberger, J.; Baas, P.; Jansen, S.; Smets, E.. |
| The systematic significance of wood anatomical characters within Ericales is evaluated using separate and combined parsimony analyses including 23 wood characters and 3945 informative molecular characters. Analyses of wood features alone result in poorly resolved and conflicting topologies. However, when pedomorphic character states are coded as inapplicable, the combined bootstrap topology results in an increase of resolution and support at most deeper nodes compared with the molecular analyses. This suggests that phylogenetic information from the limited number of morphological characters is not completely swamped by an overwhelming amount of molecular data. Based on the morphology of vessels and fibers, and the distribution of axial parenchyma, two... |
| Tipo: Article / Letter to the editor |
Palavras-chave: Anatomy; Phylogeny; Ericales; 42.48. |
| Ano: 2007 |
URL: http://www.repository.naturalis.nl/record/422235 |
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| Lens, F.; Jansen, S.; Huysmans, S.; Robbrecht, E.; Smets, E.. |
| The Vanguerieae is a large tribe of the subfamily Ixoroideae (Rubiaceae) and consists of about 500 species in 27 genera. This study gives a detailed pollen morphological description of 30 species from 16 genera, based on light microscopy and scanning electron microscopy. The Vanguerieae are considered to be stenopalynous, although there is some evidence to question this. First, there is a difference in sexine types that clearly de® nes Keetia and Psydrax ( both reticulate) , and Canthium and Vanguerieae (both perforate with very small perforations) from the other Vanguerieae investigated. Second, pollen grains corroborate the subgeneric delimitations of Canthium sensu Bridson. Pollen morphologically the tribe is characterised by ( 1) the shape of the... |
| Tipo: Article / Letter to the editor |
Palavras-chave: Vanguereae; Ixoroideae; Rubiaceae; Pollen; Morphological variation; Stenopalynous; 42.58. |
| Ano: 2000 |
URL: http://www.repository.naturalis.nl/record/423771 |
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| Vinckier, S.; Cadot, P.; Smets, E.. |
| In the anthers of flowering plants, gymnosperms, and seed ferns, tiny (¡1 mm) granules might occur on the radial and innermost tangential wall of secretory tapetum cells. These sporopollenin granules develop simultaneously with the pollen exine and are called orbicules or Ubisch bodies. The present paper focuses on two quite different topics associated with orbicules. The morphological and ultrastructural diversity of orbicules in the order Gentianales is summarized, and it is demonstrated that orbicules are a plesiomorphic feature in the order. Furthermore, orbicule characters seemed to be correlated with evolutionary trends in pollen dispersal unit and tapetum type features. In the second part, we report on our investigation of Corylus avellana L.... |
| Tipo: Article / Letter to the editor |
Palavras-chave: Orbicules; Morphology; Diversity; Gentianales; Plesiomorphic feature; Pollen; Corylus avellana L.. |
| Ano: 2005 |
URL: http://www.repository.naturalis.nl/record/407306 |
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| Simpson, D.A.; Muthama Muasya, A.; Alves, M.V.; Bruhl, J.J.; Dhooge, S.; Chase, M.W.; Furness, C.A.; Ghamkhar, K.; Goetghebeur, P.; Hodkinson, T.D.; Marchant, A.D.; Reznicek, A.A.; Nieuwborg, R.; Roalson, E.H.; Smets, E.; Starr, J.R.; Thomas, W.W.; Wilson, K.L.; Zhang, X.. |
| Since the Monocots II meeting in 1998, significant new data have been published that enhance our systematic knowledge of Cyperaceae. Phylogenetic studies in the family have also progressed steadily. For this study, a parsimony analysis was carried out using all rbcL sequences currently available for Cyperaceae, including data for two new genera. One of the four subfamilies (Caricoideae) and seven of the 14 tribes (Bisboeckelereae, Cariceae, Cryptangieae, Dulichieae, Eleocharideae, Sclerieae, Trilepideae) are monophyletic. Subfamily Mapanioideae and tribe Chrysitricheae are monophyletic if, as the evidence suggests, Hellmuthia is considered a member of Cypereae. Some other features of our analysis include: well-supported Trilepideae and... |
| Tipo: Article / Letter to the editor |
Palavras-chave: Cyperaceae; Monocotyledons; Phylogeny; RbcL; Sequence; 42.48. |
| Ano: 2007 |
URL: http://www.repository.naturalis.nl/record/414071 |
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| Lens, F.; Luteyn, J.L.; Smets, E.; Jansen, S.. |
| The ecological wood anatomy of 128 vaccinioid wood samples (including 115 species, 35 genera), collected between 39°S and 60°N latitude and 10 m to 3400 m altitude is studied. Several wood anatomical features within the subfamily, viz. tangential vessel diameter, average length of tracheary elements, height of multiseriate rays, and presence of prismatic crystals are negatively correlated with increasing latitude, while vessel density and helical thickenings show a positive correlation with increasing latitude. Similar latitudinal trends are found within the genus Vaccinium (31 species studied). The correlation between various wood anatomical features and latitude is surprisingly high despite the fact that most tropical species grow in montane regions,... |
| Tipo: Article / Letter to the editor |
Palavras-chave: Altitude; Ecological and functional wood anatomy; Ericaceae; Latitude; Vaccinioideae; Vaccinium; 42.58. |
| Ano: 2004 |
URL: http://www.repository.naturalis.nl/record/424624 |
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| Merckx, V.; Schols, P.; Maas - Van de Kamer, H.; Maas, P.; Huymans, S.; Smets, E.. |
| The mycoheterotrophic Burmanniaceae are one of the three families currently recognized in the order Dioscoreales. Phylogenetic inference using nucleotide sequences of the nuclear 18S rDNA region and the mitochondrial nad1 b-c intron revealed two well-supported, major lineages within the family, corresponding to the two tribes recognized in the family: Burmannieae and Thismieae. All data supported a strong relationship between Thismieae and Tacca (Dioscoreaceae) making both Burmanniaceae and Dioscoreaceae polyphyletic. The three largest Burmanniaceae genera, Burmannia, Gymnosiphon, and Thismia, are paraphyletic. The splitting of Burmanniaceae into Burmannieae and Thismieae indicates two independent origins of mycoheterotrophy and correlated loss of... |
| Tipo: Article / Letter to the editor |
Palavras-chave: 18S rDNA; Burmanniaceae; Dioscoreales; Molecular phylogeny; Mycoheterotrophy; Nad1 b-c intron; Thismiaceae; 42.48. |
| Ano: 2006 |
URL: http://www.repository.naturalis.nl/record/422338 |
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| Rabaey, D.; Huysmans, S.; Lens, F.; Smets, E.; Jansen, S.. |
| Recent studies on the functional significance of pit membranes in water conducting cells have renewed general interest in their micromorphology. At least two types of pit membrane thickenings have been described in angiosperm families, i.e. genuine tori and pseudo-tori. This study explores the distribution and morphology of pit membrane thickenings in 69 species and 23 genera within Oleaceae using light and electron microscopy. Torus-bearing pit membranes are confirmed for Osmanthus, and new records are reported for Chionanthus retusa, Picconia azorica, and P. excelsa, but not for the other species studied of Chionanthus. This infrageneric variation suggests that tori represent a plastic feature that has evolved more than once within the family as the... |
| Tipo: Article / Letter to the editor |
Palavras-chave: Electron microscopy; Pit aperture; Pit membrane; Plasmodesmata; Pseudo-torus; Torus; Tracheid; Vessel element; 42.56. |
| Ano: 2008 |
URL: http://www.repository.naturalis.nl/record/429536 |
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| Lens, F.; Smets, E.; Melzer, S.. |
| The soc1 ful double mutant of A. thaliana produced substantial secondary growth throughout all aboveground stems, whereas in the Col accession only a few cell layers of wood were produced at the base of old stems. This increased wood formation may be linked to inactivation of the flowering time genes SOC1 and FUL (Melzer et al., 2008). These two genes could play a crucial regulatory role in triggering genetic mechanisms that lead to insular woodiness outside A. thaliana, and this ‘simple’ two-gene loss could explain why many nonrelated herbaceous families have independently evolved into woody insular lineages throughout the world. However, SOC1 and FUL might not be the only suppressors of cambium formation; other upstream, downstream or parallel-acting... |
| Tipo: Article / Letter to the editor |
Palavras-chave: Stem anatomy; Arabidopsis thaliana; Insular woodiness; Brassicaceae; Wood formation; 42.56. |
| Ano: 2012 |
URL: http://www.repository.naturalis.nl/record/429528 |
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| Lens, F.; Jansen, S.; Caris, P.; Serlet, L.; Smets, E.. |
| The wood structure of 78 species from 27 genera representing the woody primuloids (Maesaceae, Myrsinaceae, and Theophrastaceae) was investigated using light microscopy (LM) and scanning electron microscopy (SEM). Results indicated that the ray structure, the nature of mineral inclusions, and the occurrence of breakdown areas in rays can be used to separate the three primuloid families from each other. Within Ericales, the presence of exclusively multiseriate rays is synapomorphic for Myrsinaceae and Theophrastaceae, and the occurrence of breakdown areas in rays is synapomorphic for Myrsinaceae. Within Myrsinaceae, the wood structure of the mangrove genus Aegiceras differs because it has short vessel elements that are storied, non-septate fibers, a... |
| Tipo: Article / Letter to the editor |
Palavras-chave: Primuloids; Ericales s.l.; Maesaceae; Myrsinaceae; Theophrastaceae; Wood anatomy; Comparison; Light microscopy; Scanning electron microscopy. |
| Ano: 2005 |
URL: http://www.repository.naturalis.nl/record/407307 |
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| Lens, F.; Gasson, P.; Smets, E.; Jansen, S.. |
| The wood anatomy of 16 of the 37 genera within the epacrids (Styphelioideae, Ericaceae s.l.) is investigated by light and scanning electron microscopy. Several features in the secondary xylem occur consistently at the tribal level: arrangement of vessel‐ray pits, distribution of axial parenchyma, ray width, and the presence and location of crystals. The primitive nature of Prionoteae and Archerieae is supported by the presence of scalariform perforation plates with many bars and scalariform to opposite vessel pitting. The wood structure of Oligarrheneae is similar to that of Styphelieae, but the very narrow vessel elements, exclusively uniseriate rays and the lack of prismatic crystals in Oligarrheneae distinguish these two tribes. The secondary xylem of... |
| Tipo: Article / Letter to the editor |
Palavras-chave: Ecological wood anatomy; Epacrids; Ericaceae s.l.; Styphelioideae; Systematic wood anatomy; 42.56. |
| Ano: 2003 |
URL: http://www.repository.naturalis.nl/record/431740 |
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| Groeninckx, I.; Janssens, S.; Smets, E.; Verstraete, B.. |
| Astiella is an herbaceous genus endemic to Madagascar, originally described with a single species A. delicatula Jovet. Molecular and morphological evidence place it in the tribe Spermacoceae s. lat. of Rubiaceae. During herbarium studies and fieldwork in Madagascar, 11 new Astiella species were identified and these are described here: A. antongilensis Groeninckx sp. nov., A. antsalovansis Groeninckx sp. nov., A. confusa Groeninckx sp. nov., A. deblockiae Groeninckx sp. nov., A. desseinii Groeninckx sp. nov., A. homolleae Groeninckx sp. nov., A. latifolia Groeninckx sp. nov., A. longifimbria Groeninckx sp. nov., A. perrieri Groeninckx sp. nov., A. pulla Groeninckx sp. nov., and A. tsaratanensis Groeninckx sp. nov. The genus Astiella now holds 12 species in... |
| Tipo: Article / Letter to the editor |
Palavras-chave: Astiella; Endemism; Madagascar; Rubiaceae; Spermacoceae s. lat.. |
| Ano: 2017 |
URL: http://www.repository.naturalis.nl/record/629097 |
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| Wilkin, P.; Schols, P.; Chase, M.; Chayamarit, K.; Furness, C.; Huysmans, S.; Rakotonasolo, F.; Smets, E.; Thapyai, C.. |
| Following recent phylogenetic studies of the families and genera of Dioscoreales, the identification of monophyletic infrageneric taxa in the pantropical genus Dioscorea is a priority. A phylogenetic analysis based on sequence data from the plastid genes rbcL and matK is presented, using 67 species of Dioscorea and covering all the main Old World and selected New World lineages. The analysis used 14 outgroup taxa, including Trichopus Gaertn., Tacca J.R. & G. Forster, Stenomeris Planch., Burmannia L. and Thismia Griff. The main findings are: a) that a clade of rhizomatous taxa is sister to the rest of Dioscorea; b) the main Old World groups (such as the right-twining D. sect. Enantiophyllum) are monophyletic and c) there are two distinct lineages among... |
| Tipo: Article / Letter to the editor |
Palavras-chave: Dioscorea; Phylogeny; Classification; Analysis; Plastid genes; RbcL; MatK; Character evolution. |
| Ano: 2005 |
URL: http://www.repository.naturalis.nl/record/407311 |
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| Lens, F.; Jansen, S.; Robbrecht, E.; Smets, E.. |
| The Vanguerieae is a tribe consisting of about 500 species ordered in 27 genera. Although this tribe is mainly represented in Africa and Madagascar, Vanguerieae also occur in tropical Asia, Australia, and the isles of the Pacific Ocean. This study gives a detailed wood anatomical description of 34 species of 15 genera based on LM and SEM observations. The secondary xylem is homogeneous throughout the tribe and fits well into the Ixoroideae s.l. on the basis of fibre-tracheids and diffuse to diffuse-in-aggregates axial parenchyma. The Vanguerieae include numerous geofrutices that are characterised by massive woody branched or unbranched underground parts and slightly ramified unbranched aboveground twigs. The underground structures of geofrutices are not... |
| Tipo: Article / Letter to the editor |
Palavras-chave: Vanguereae; Rubiaceae; Systematic wood anatomy; Geofrutex; 42.58. |
| Ano: 2000 |
URL: http://www.repository.naturalis.nl/record/423793 |
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| Registros recuperados: 59 | |
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